Pectoralis major ruptures are considered to be significantly rare types of sports injuries. These
specifically occur on contact, caused by a sudden, violent
contraction of the muscle, usually with particular stretching positions, such
as during the bottom of a bench press or during tackling in rugby or football.
Although pectoralis major ruptures are believed to be uncommon injuries, these have
become more frequent with the growing popularity of contact sports, such as
body combat sports and weight training.
Anatomy and Biomechanics
The pectoralis major muscle is made up of two recognizable heads; the
clavicular head and the costosternal head. The clavicular head emerges from the
medial clavicle and the upper sternum while the costosternal head on the
sternum emerges from the aponeurosis of the external oblique and the first six
costal cartilages of the rib cage. They both incorporate to form the anterior wall
and fold of the axilla, extending across the shoulder and inserting onto the
proximal humerus.
The clavicular and upper sternal portion of the muscle precisely inserts on the humerus below the introduction of the lower sternal and external oblique
fibres. Each distinct tendon divides onto each other approximately 90 to 180
degrees before being introduced on the humerus. Through a study utilizing fine
wire gauges, research determined that the sternocostal head and its tendon
stretch unevenly in the last 30 degrees of humeral extension in comparison with
the clavicular head. Because of this, the sternocostal head has a higher risk
of injury and rupture as it is most exposed to intense stretches. In addition,
this also shows that partial ruptures of the tendon are more common than the
complete rupture of both heads.
The pectoralis major is a powerful internal rotator, adductor and flexor
of the shoulder. It acts to support the shoulder in contact sport conditions.
Researchers demonstrated, however, that the pectoralis major is not as essential
towards normal shoulder function as other shoulder muscles. It is necessary
though for strenuous physical activities which indicates that some athletes may
require surgical repair while others may respond well to conservative treatments.
Injuries to the pectoralis major include contusions or sprains, partial
tears, complete tears, muscle origin tears, muscle belly tears or the
development of musculotendinous junction, or MTJ. Most frequently, ruptures of
both heads are not seen where only the inferior fibres of the sternocostal head
has ruptured, giving an incorrect perception that the entire tendon still
remains intact. Complete ruptures almost always include an avulsion of the
humeral enthuses.
Demographics
Pectoralis major ruptures have become more prevalent in the last few
decades, now more common among athletes ranging from the ages of 20 to 40,
which suggests that athletic behavior may be the main underlying risk factor
for tendon injury. Moreover, pectoralis major ruptures appear to affects males
much more than females.
A study found that 50 percent of individuals were initially
misdiagnosed. The presenting signs and symptoms of an injury are essential when
dealing with acute soft tissue trauma, particularly in athletes. It’s been demonstrated
that delaying treatment as a result of misdiagnosis can result with improper
functional outcomes.
Mechanism of Injury
Pectoralis major ruptures are generally caused by a sudden forceful
overload of the muscle in a maximally contracted position or due to direct
contact with the muscle while it is in a stretched position. Stretch and load
type injuries often result in injuries to the insertion and musculotendinous
junction whereas direct blows tend to injure the muscle belly.
Exemplary mechanisms of injury include: tackling in contact sports such
as rugby and football; bench pressing,
specifically at the bottom or if the weight is suddenly bounced off the chest
or if the lifter arches the spine; water skiing or windsurfing, specifically if
the arm is externally rotated, extended and a sudden stretch is applied due to
a fall or jolt; and wrestling, specifically if the arm is caught in an abnormal
position.
It has been proposed that a normal, healthy tendon can be resistant to
rupture and that degeneration must be present in order for the tendon to suffer
injury. Constant weight training may expose the tendon to multiple loads of
pressure and stress which may lead to the start of tendon degeneration and the
occurrence of pectoralis major ruptures can usually follow tendon degeneration.
Symptoms of Pectoralis Major Ruptures
Individuals with pectoralis major ruptures generally describe symptoms
of sudden, sharp pain in the region of the upper chest along the shoulder,
typically reported when the arm is caught in a stretched and powerfully
contracted position. This can be usually associated with a ripping or popping
sensation.
Because of the pain, many affected individuals may refuse to move their
injured shoulder, causing a discoloration of the skin in the region of the
axilla and upper bicep.
An evaluation may display a thin, axillary fold, a sulcus or a groove in
the area where the deltoid and pectoral muscle cross. Active contractions of
the muscle often show bulging in the anterior chest wall. The examination can
be performed by having the affected individual press their hands together in
front of the body, producing an isometric contraction of the muscles.
Range of motion shoulder movements into abduction and external rotations
may be greatly limited by symptoms of pain, however, the individual’s range of
movement may recover quickly. In other instances, weakness during internal
rotations may be present, particularly when internal rotation is evaluated with
the arm in a neutral rotation.
Treatments
Only utilizing X-rays may be inconclusive when determining the presence
of pectoralis major ruptures, but, it’s been hypothesized that a missing
pectoral shadow displayed on X-ray results may suggest a rupture of the
pectoral tendon. Ultrasounds can help visualize the tear, showing a thinning of
the muscle. Computerized tomography, or CT, scans may show a disruption of the
muscle tendon. MRI is the most accurate imaging modality, with axial T2
weighted images being most effective for acute injuries and T1 weighted images
being most recommended for chronic injuries. MRI may also display muscle belly hematoma,
also used to confirm which individuals will benefit from surgical treatments.
Surgery has been a preferred method of treatment among the athletic
population. For those who’ve chosen conservative treatment options, there’s
been a reported peak force production reduction in their work capacity when
measured on isokinetic devices. Partial tears of the belly muscle or distal
partial tears in non-athletic individuals may experience a positive outcome
when treated conservatively. It’s also been suggested that longer periods of
delayed treatment can make rehabilitation of a torn tendon difficult. It’s
recommended to treat an injury as soon as possible.
Surgery for this type of injury involves a 5 to 8 cm incision in the
deltopectoral crease line. The tendon should be properly examined during
surgery with the arm carefully abducted and externally rotated since
costosternal head tears are often hidden by the clavicular head if the arm is
by the side. The full length of the tendon and musculotendinous junction, or
MTJ, must be properly analyzed to determine the precise site of the tear. MTJ
injuries are repaired using permanent sutures.
In the case the tendon ruptures at the attachment of the bone, then, the
lateral lip of the bicipital groove is uncovered and cleared of soft tissue.
Suture anchors and drill holes are utilized to re-attach the tendon onto the
bone. Frequently, full tendon tears may need up to four suture anchors.
Post-Surgery Rehabilitation
After surgery, the individual may be
recommended to rest their arm in a sling for up to four to six weeks, using
either a sling immobilizer or a basic sling. Ruptures within the soft tissues
may need longer period of immobilization in comparison with direct tendon into
bone ruptures. It’s believed that direct tendon into bone attachments are more stable
than within soft tissue repairs. Post-surgery rehabilitation goals include:
maintaining the integrity of soft-tissues post repair; restoring full range of
movement; restoring muscle control and regaining strength; and return to full,
unrestricted athletic participation.
Range of Motion Progressions
The fundamental purpose of rehabilitation
involves tissue protection to allow the sutured tendon fibres to heal
accordingly. The individual will be immobilized in a sling and no passive or
active movements should be allowed for the first 2 weeks. After 3 weeks, gentle,
passive range of motion procedures into external rotation, flexion and
abduction can be utilized.
From weeks 2 to 3 onwards, the passive range
of movement progressions are slowly opened into external rotation, abduction
and flexion. Once the individual achieves the desired range of movement for
that week, they may be allowed to participate actively within gravity-assisted/resisted
positions. At first, the individual’s range of motion exercises can be guided
by a therapist, or in many cases, with the help of a chiropractor or other soft
tissue specialist, to avoid the risk of further injury. Once the individual
achieves a desired passive range, they may carefully use that range actively.
The aim is to have full active/passive movements by the 12th
post-operative week.
Chiropractic and Physiotherapy Interventions
Since the surgical procedure is introduced
into the shoulder joint itself, the procedure is considered to be
extra-capsular, therefore, shoulder joint effusion and intraarticular adhesions
are not present. As the surgical technique involves significant excision of the
soft tissues to access the torn pectoralis tendon, adhesions are common in the
fascia and surrounding soft tissues. Safe mobilizations are encouraged to
prevent excessive adhesion formations that would otherwise result in complete
immobilization. Gentle, passive movements are believed to promote collagen
repair and allow the scar tissue to heal.
Gentle scar tissue massages through the pectoral
muscle can initiate at week 3 to regulate post-surgery muscle tone and to
mobilize the scar tissue. Initially, this may be considerably painful due to
the trauma, however, this can also progressively become more aggressive in the
form of deep cross friction, continuous ultrasound and tooling used by
specialists, even chiropractors or physical therapists may utilize these
procedures.
Deep soft tissue procedures to the pectoralis
major can be gradually added along with regular massage, to all other
shoulder/scapular muscles that may become shortened as a result of the limited
mobility, including the pectoralis minor, latissimus dorsi, upper trapezius,
infraspinatus and the subscapularis.
When the individual’s range of movement begins
to improve, it may be required by the chiropractor to begin direct glenohumeral
joint accessory mobilizations to improve the health of the surrounding
structures. It may be further required to mobilize the cervical and thoracic
spine with the articulations of the rib as these may also become tightened and
restricted as a result of early mobility.
In more advanced stages, once the individual’s strength and original
range of motion has been established, the therapist or chiropractor may be
required to use manual strengthening procedures.
Strengthening Progressions
To avoid further injury of the sutured muscle/tendon/bone tissues, no
direct pectoralis major contractions should be allowed for the first six weeks following
a surgery. Isometrics may be initiated for other surrounding muscles as long as
the arm remains in a stable range for that week. Isometric scapular setting,
shoulder abduction, extension, external rotation will manage tone in the
surrounding shoulder muscles.
From week 6 onwards, the individual can
initiate isometric pectoralis major contractions while in a shortened position,
also utilizing muscle stimulators. The strength of the contraction can be
progressed almost daily. Scapular exercises may be added through all scapular
ranges of protraction/retraction, upward/downward rotation and
depression/elevation. Weight may also be gradually increased for the external
rotation, abduction and extension activities, as long as the arm does not
exceed the allowed range for that week.
By week 8, the introduction of careful Thera
band exercises for the pectoralis major can be implemented, such as internal
rotation, adduction and flexion. From week 8, the affected individual may also
begin gentle proprioceptive-type exercises to maintain a safe range of movement
for the arms. These can be simple eyes-closed reach-and-feel type drills that
retrain position awareness.
From week 12, light exercises using a dumbbell may be utilized to apply
careful weight into the planes of movement. The arrangement of strength
recovery in strength training which can allow a safe adaptation of all shoulder
muscles and protect the pectoralis major would be: horizontal pulling, such as
rowing, one arm row and prone flies; horizontal pushing, such as shoulder press
and dumbbell raises; vertical pulling, such as chin ups and pulldowns; and
horizontal pressing, such as bench press and all the variations. High load
pectoralis exercises under long levers should be avoided for six months.
Additionally, at week 12, the individual will be required to begin more
advanced proprioceptive-type shoulder exercises. These may include holding specific
positions on BOSU balls and alphabet writing with the hand on a SWISS ball.
Plyometric-type drills can initiate with light weights or loads at week
13 and more aggressive plyometrics would need to be delayed until the affected
individual has reasonable bench press strength. These would include explosive
push-ups, and bench throws with a Smith machine bar.
By week 14, PNF repeat contractions may start as long as the individual
has full movement into abduction, external rotation.
Following these from week 18, the individual will start with therapies
of light resistance and progress to maximum resistance. The PNF pattern starts
with the individual’s arm in flexion/abduction/external rotation. The therapist,
or chiropractor, can then apply pressure in the individual’s hand and on the
arm. The patient then actively contracts into adduction and internal rotation.
This movement is gently resisted by the therapist, or chiropractor. The common
program consists of 3 sets of 10 contractions. The chiropractor can increase
their manual resistance as a progression.
F/ABD/ER into E/ADD/IR Exercise
Shoulder Strengthening with Weights
After the athlete has followed the series of rehabilitation procedures
throughout each week, a specialist, or other healthcare professional including
chiropractors, may recommend an additional series of shoulder strengthening
exercises to improve the function of the structures and tissues surround an
athlete’s pectoralis major ruptures. The use of a dumbbell should be carefully
considered and only utilized under the direct instruction of a specialist.
Cross Training
As for cross training exercises following surgery
for pectoralis major ruptures, in the early stages, cardio exercises which do
not require the use of the arms can be started, such as the utilization of a
stationary bike and water running with the arm kept against the stomach.
Cardio movements that require arm motion
should be below the 90-degree shoulder plane by around week 10.
More direct arm cardio exercises, such as
grinder, can be started by week 12, swimming, can be started by week 14 and
boxing, which can be started by week 16, may be delayed until the end.
Return to Sport
According to the type of sport or physical
activity the athlete participates in, this phase can be essential, most frequently because most pectoralis major ruptures can occur in individuals whom
participate in rugby or football.
The key times and dates to implement return to sport procedures are: week 8,
treadmill running with the arm in a protected posture; week 10, treadmill
running with a short arm swing; week 12, unrestricted field running, not
sprints; week 14, non-contact catch/pass drills and sprinting; week 16,
initiating controlled contact training with 4 week progressions; and week 20 to
24, return to play if all other objectives have been met.
Pectoralis major ruptures are uncommon
injuries, however, they do occur during sports and physical activities, such as wrestling,
skiing, rugby and bench pressing. The greater part of complete and even incomplete
ruptures typically need surgery. Rehabilitation procedures are comprehensive,
involving the recovery of the individual’s original range of movement,
strength and function. Rehabilitation and return to sport can generally take up
to 4 to 6 months for the active athletic population.
By Dr. Alex Jimenez
